In the following pack of files include every piece of music and sound effect from Sonic 2 ported to work in 68k SMPS format, as well as edits to the sound driver to include the extra DAC samples used in the game. Admittedly, not all of these are 100% perfect; in a few cases the tempo is off by a few ticks and a couple of sound effects have issues we were never able to fully work out for whatever reason. However, this is a very strong and acceptable basis to throw into any hack and have the results largely indistinguishable from the original game. Ideally speaking, anyone using this driver in their hack is going to replace the music anyway, so this is very likely to be a non-issue.
Sonic 2 Clone Driver
NOTE: This requires having already ported the Sonic 1 sound driver to your hack to actually work.
To use the clone driver, simply replace the relevant files in your disassembly with the ones included in this pack. We used jman's custom DAC driver to simplify adding the new samples; you're free to replace this if you wish, but it should work fairly well for any given purpose.
Credits go to myself and Puto for the music ports and driver edits, and jman for the custom DAC driver and 68k frontend. If you decide to use this in your hack, do us a favor and leave us a small mention—we'd appreciate it.
Enjoy! Hope to see this put to good use.